202 Offspn7ig of a Dimuf Bearing Strain of Guinea Pigs 



The proportion of normal offspring to dwarfs is 3:1. That the 

 numbers in the total are in exactly this proportion is of course merely 

 a coincidence. 



The preponderance of male dwarfs and of the total number of males 

 is very considerably diminished since the last report. 



If we consider separately the offspring in families in which the 

 dwarfs were all male, in those in which the dwarfs were all female and 

 in those in which the dwarfs were of both sexes, we find that the excess 

 of males is confined to the first set of families, i.e. those in w^hich the 

 dwarfs were all male. In this total the males are more than three 

 times as numerous as the females. In the earlier experiments most 

 of the fxmilies were of this kind ; the diminution in the excess of males 



(2) Families cunlaimiuj dwarfs of both sexes. 



Offspring 



(3) Families coiUainiity besides nor'mal offsjjrhuj male dwarfs only. 



Offspring 



Totals ... 17? 33 cT 21 <? 



Total 54 d" : 17 ? , a fairly close approximation to a 3 : 1 ratio. 



